Yoshida - 1981 - Fundamentals of Rice Crop Science

60 FUNDAMENTALS OF RICE CROP SCIENCE
1.50. Grain growth of rice at 2
locations. T is the effective grain
tilling period (IRRI 1978).
ripening period because most of the dry grain weight is attained during the
effective grain-filling period. Effective grain filling lasts about 23 days for IR20 at
Los Baños, Philippines, and 33 days for Tongil at Suweon, Korea. The rates of
increase in grain weight are almost identical at the two locations, i.e., about 26-27
g/m 2 per day. The grain growth rate is only slightly less than the maximum crop
growth rate normally achieved during the vegetative growth stage, i.e., about 30
g/m 2 per day.
1.12. YIELD AND YIELD COMPONENTS
1.12.1. Yield
Rice yield is usually reported as rough rice (paddy) at 14% moisture content,
except in a few countries, such as Japan and Korea, where yield is expressed in
terms of brown rice or sometimes in terms of polished rice. A conversion factor of
1.25 is usually used when brown-rice yield is converted to rough-rice yield.